Aeroplane



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' AEROPLANE Filed July 29, 1929 2 Sheets-Sheet 2 /vve on WWWM HLHUHHU I luv Patented Aug. 25, 1931 UNITED T OFFICE AEROPLANE Application filed July 29, 1929, Serial No.

This invention relates to aeroplanes either of the monoplane or biplane type and has reference more particularly to a method of securing the aerofoil or aerofoils to the fuselage whereby the angle of incidence may be varied, within the limits, by and at the will of the pilot.

At the present time the aerofoils are fixed either directly or indirectly to the body of the aeroplane and the angle of incidence cannot therefore be altered by the pilot. Practical experience has enabled manufacturers to determine the most efficient angle of incidence but it is such that for the aerofoils to exert their lifting power it is essential that a flying speed of approximately 40 M. P. H. be maintained; this speed however is dangerous when landing and is attended by a large amount of chance. These remarks are also largely applicable in regard to taking off.

It is known to use two aerofoils, one behind and slightly below the other with an intervening adjustable aerofoil capable of being moved so as to form what might be termed a connection whereby the three aerofoils become as one with an increased angle of incidence. This arrangement will of course give a greater lifting area but its efficacy in practical use is not yet known.

The objects of my invention are to give the pilot better control over the machine by providing a means whereby he may ad ust and hold the aerofoil at an angle such that it will maintain its lifting power and thereby enable him to land or take off at a slower and safer speed than has hitherto been possible and without altering the superficial area of aerofoil. A further object of the invention is to provide a means for stabilizing a machine whilst landing or taking off, and to so arrange those means that whilst they will be automatically operated they will still be under the control of the pilot.

It consists in pivotally connecting the aerofoil or aerofoils to a supporting frame that is fixed to the body of the machine. For light =machines the wheels may be carried by a movable frame to which the aerofoil is attached but in the heavier types they would be car- 381,835, and in Australia October 8, 1928.

ried by a. frame that is fixed to the body of the machine. It also comprises a stabilizing rudder and means for automatically and manually operating the same.

Obviously there are numerous ways in which the invention may be applied and the methods of construction will necessarily differ with every type of aeroplane.

In the accompanying drawings v Figure 1 is a perspective view showing in dotted lines, the outline of an aeroplane, the general disposition of some of the parts that constitute this invention being shown in hard lines.

Figure 2 is a side elevation of part of Figure 1 but showing additional details.

Figure 3 is a front elevation of Figure 2.

Figure 4 is a plan view of twin rudders which are automatically operated when the angle of incidence of the aerofoil is changed, but which still remain independently operable by the pilot for further movement.

Figure 5 is a perspective view showing how the rudders may still be operated by the pilot even though they have been moved automatically and are held temporarily through the pilots action of changing the angle of incidence of the aerofoil.

The aeroplane selected for the purpose of describing and illustrating the invention is of the monoplane type wherein the aerofoil 10 is secured indirectly to and above the body 11 of the machine. It will be obvious that if the aerofoil is pivotally mounted the stay rods cannot be attached to the body and in order to obviate that difficulty a U shaped metal frame 13 is provided the upper ends of such frame being rigidly secured at 14a to the longitudinal spars 14 of the aerofoil 10. The frame 13 will be of dimensions that will enable the body 11 to lie freely therein and its lower end to swing forwardly from its normally vertical position without fouling the body. At each side of the body 11 two vertical members 16 are rigidly secured in any suitable manner. These vertical members will be strengthened by stays 17 the upper ends of which may be integral with or rigidly secured to the upper ends of the respective vertical members and the lower ends to the body 11. Two of the ribs 15 adjacent to the centre of the aerofoil may be provided with lugs or brackets 18 to enable the aerofoil to be pivotally connected at 19 to the upper ends of the respective vertical members 16 or the latter'may be pivoted to a vertical face of the respective ribs, according to the particular formation of the rib. The movement of the aerofoil 10 in order to alter the angle of incidence thereof is brought about by means of a pair of levers 21 and connecting links 22 which are operated by a worm 23 and quadrantal worm gear 2 1. The levers 21 are keyed or otherwise rigidly secured to and near the respective ends of a hollow shaft 25 which is rotatably mounted in bearings 26 formed in or carried by the vertical members 16. The quadrantal worm gear 24 is fixed in any appropriate manner to and concentrically with the shaft 25 at or about its longitudinal centre. The worm 23 will be formed upon or rigidly secured to and near one end of a shaft 27 that is mounted in bearings formed in two transverse members 28 the endsof each of which will be rigidly secured to the respective vertical members 16 or to any other convenient fixtures that are secured to the body 11 of the machine. The shaft 27 will be of a suitable length and will project rearwardly, its rear extremity being provided with a hand Wheel 29 so positioned that it may be conveniently manipulated by the pilot. The worm 23 will mesh with the worm gear 24 so that as the pilot turns the hand wheel 29 in one direction the shaft 25 will be caused to partly rotate in its bearings 26 and in doing so will carry with it the levers 21 one end of each of which will move upwardly through an arc whilst their opposite ends will move downwardly through an arc. This movement will be transmitted to the connecting links 22 and to the aerofoil l0 and the angle of incidence will be thereby increased according to the amount of movement imparted to the hand wheel 29. To return the aerofoil to its normal position the wheel 29 will be turned in the opposite direction and a stop may be secured to the side of the Worm gear 24 and project radially therefrom so as to strike the foremost transverse member 28 in order to prevent the aerofoil being moved backwardly beyond the normal angle of incidence.

It will be seen that when the angle of incidence is altered as shown by dotted lines in Figure 2 the underside of the aerofoil will offer a greatly increased resistance to the air and the speed must therefore be reduced ac cordingly but the increased angle of incidence will cause the aerofoil to exercise a greater lifting power and the tendency of the machine will be to lift even at a much reduced speed. In this manor by the use of this invention greater safety is afforded when landing or taking off. The reduced speed however will cause the tail to oscillate or wobble and the present form of rudder would not be capable of stabilizing the machine against such movement. It is therefore an object of this invention to provide a means for stabilizing an aeroplane againstlateral movement in a horizontal plane when it is travelling at slow speeds. The means provided comprise a pair of vertically positioned lat eral steering rudders 30 and 31 which are hingedly secured at 32 to the rear vertical edge of the tail fin 33. It is necessary that these rudders 30 and 31 should be located equally above and below the elevating rudder 34-3 10 and in order to permit each of the rudders 30 and 31 to be made in one piece the elevating rudder will be made in two pieces 3l34a, the adjacent ends of both parts being cut away diagonally in a manner known and understood to form an angular recess 35 which will enable the rudders 30 and 31 to lie normally in a vertical plane passing through the longitudinal centre line of the machine and to be moved outwardly from one another as required. The respective rudders 30 and 31 will be provided with an outwardly projecting arm 30a and 31a to which one end of the respective steering ropes or wires 36 and 36a will be attached in any convenient manner, the other ends thereof passing around the pulley wheels 37-37d that are secured to the respective vertical members 16 or to any suitable frame member of the body and then securely fastened to the foremost ends of the respective levers 21. The ropes or wires 36 and 36a should be taut when the rudders 30 and 31 are closed together and the levers 21 are at their normal position as shown at Figure 2, so that when the hand wheel 29 is turned it will move the levers 21 as previously explained but as both the ropes or wires 36 and 36a are taut they must also move with the levers and thereby cause the rudders 30 and 31 to move through an arc outwardly from one another according to the amount of movement imparted to the levers 21. The rudders 30 and 31 being thus moved at an angle to longitudinal line of the body will cause an equal wind pressure upon each of their outer surfaces and the machine will be thereby steadied on her course. This movement of the rudders it will be seen is automatic but it is also necessary that they should remain separately under the control of the pilot. For this purpose a pair of pedals 3838a are pivotally secured at 39 and 39a respectively to a portion of the body frame 40 or floor of the cock pit. The stem 41 of each of the pedals is provided with an outwardly projecting arm 12 at the other extremity of each of which an eye 13 is formed and separate lengths of wire or rope i4 connect the stems ll of the pedals 38 and 38a to the respective ropes or wires 36 and 36a at a point Z rearwardly of the respective pedals 38 and 38a and pulley wheels 37 and 37a. Those portions of theropes or wires 36 and 36a lying between the levers 21 and pulley wheels 37 and 37a will pass through the respective eyes 43. The reason for this arrangement of parts is that when the rudders 30 and 31 are at the normal position and it becomes necessary for the pilot to steer to the right or to the left he may depress the right or left pedal and one of the ropes or wires 44, according to which pedal is operated will pull on that portion of the rope or wire lying behind the connecting point Z and thus move one of the rudders 30 or 31. The ropes may, however, have been pulled forwardly automatically by the levers 21 when the pilot has turned the hand wheel 29 so that both the ropes 44 might be slack when the pilot finds it necessary to steer either to the right or left, in which case by depressing the correct pedal the arm 42 will be caused to move with the pedal thereby bellying that portion of the rope lying between the pulley wheel 37 or 3760 and the respective levers 21 as shown at Figure 5; this would create an additional pull on the rope 36 or 36a and one of the rudders 30 or 31, according to which pedal is being operated, would be moved to a greater angle. The arrangement might also be used when, in the pilots judgment, it is advisable to move the rudders 30 and 31 to a greater angle than that to which they are automatically carried by increasing the angle of incidence to what the pilot considers the maximum required at the moment, in which case both pedals could be depressed and both the rudders be thereby moved to the desired angle.

The invention is also applicable to a biplane and in such a case each member of the lower aerofoil could be secured to and extend outwardly from the respective lowermost side members of the frame 13. w The upper and lower aerofoils would then be secured together by vertical rods, struts and/0r wires or ropes by any known means. v

The undercarriage for the wheels may in some cases be secured to the frame 13 in any convenient manner but if it is connected to the body it will of course be necessary to allow for the necessary movement of the frame 13.

I claim:

1. An aeroplane including a body, vertical supports arranged on the body, cross bars connecting the vertical supports, an aerofoil pivoted medially of its leading and trailing edges for vertical swinging movement on the upper ends of the supports, a frame suspended from the aerofoil and arranged about the body, stays connecting the aerofoil and the lower end of the frame, a transverse shaft journalled in the vertical supports, pairs of levers extending laterally from the shaft, rods pivotally connected between the ends of the levers and the undersurface of the aerofoils, a segmental worm gear on the shaft, another shaft journalled in the cross bars, a worm on the last mentioned shaft meshing with the worm gear, and a hand wheel on the last mentioned shaft for rotating the same to adjust the inclination of the aerofoil with respect to the body.

2. In an aeroplane having a body, a recessed rear fin and having an adjustable aerofoil on the body and also provided with a pair of horizontally swingable rudders mounted in the recessed fin, manually operable means for simultaneously adjusting the angle of incidence of the aerofoil and for swinging the rudders laterally in combination with manually operable means operably connected with the main operating means for independently operating the rudders.

In witness whereof I have signed this specification.

WILLIAM HERBERT GRAY. 

